Carrier GT-G Heat Pump User Manual


 
GT-GS
50
Carrier Indoor & Outdoor Split Geothermal Heat Pumps - Rev.: 08/10/05
GT-GS Indoor Split (50YCS) Series
General
The liquid source heating/cooling split con dens ing units
shall be ARI/ASHRAE/ISO 13256-1 loop per for mance
certi ed and listed by a nationally recognized safety-
testing laboratory or agency, such as Un der writ er’s
Lab o ra to ry (UL), or Canadian Stan dards Association
(CSA-US). Each unit shall be water run-tested at the
factory. Each unit shall be pallet mounted and shipped in
clear shrink wrap for visual shipping damage inspection.
The units shall be war rant ed by the man u fac tur er against
defects in materials and workmanship for a period of ve
years on all parts, and ten years on the compressor and
refrigerant circuit parts with a service labor allowance
during the rst 30 days. An optional extended war ran ty
is available for the GT-GS
Split Series units, which adds
a labor allowance and trip charge. The liquid source
units shall be designed to operate with entering liquid
temperature between 20°F and 120°F.
Casing & Cabinet
The cabinet shall be designed for indoor installations.
The cabinet shall be fabricated from heavy-gauge
galvanized steel painted with a epoxy powder coat
paint with a 1000 hr. salt spray test rating. The interior
shall be insulated with 1/2" thick, multi-density, coated
glass ber with edges sealed or tucked under anges.
Three compressor com part ment access panels shall
be provided and shall be removable with linesets and
water piping in place. The internal com po nent layout
shall provide for major service with the unit in-place for
restricted access installations.
Refrigerant Circuit
All units shall contain split refrigerant circuits employing
a hermetically sealed com pres sor, thermal expansion
valve, reversing valve, coaxial tube water-to-refrigerant
heat exchanger, service ports, and backseating service
valves. Compressors shall be high-ef ciency advanced
scroll type designed for heat pump duty and mounted
on spring vibration isolators. Compressor motors
shall be single phase PSC with internal overload
pro tec tion. A factory installed bidirectional lter drier
shall be provided. The coaxial water-to-refrigerant
heat exchanger shall be designed for close approach
temperatures and be con struct ed of a convoluted copper
(optional cupronickel) inner tube and a steel outer
tube. The thermal expansion valve shall provide proper
superheat over the entire liquid temperature range with
min i mal “hunting”. The valve shall operate only in the
heating mode with the use of an internal check valve.
The water-to-refrigerant heat exchanger and refrigerant
suction lines shall be insulated to prevent condensation
at low liquid temperatures. Air coil con nec tions shall be
made through brass backseating service valves with
built-in Schrader ports.
Electrical
CXM Control - A microprocessor-based compressor
controller (CXM) shall be provided to monitor and control
unit operation. The control shall provide high and low
pressure monitoring, eld selectable water and air coil
low water temperature sensing, over/under voltage
monitoring, and unit performance sentinel (UPS). The
control shall also provide for water valve connection, a
test mode, short cycle protection, random start-up, as
well as fault LED, fault mem o ry, and intelligent fault retry.
The control shall employ quick attach harness
as sem blies for low voltage connections to the control
board to aid in troubleshooting or replacement. An
integral terminal block with screw ter mi nals shall
be provided on the control for all eld low voltage
connections. Line voltage lugs shall be provided for unit
wiring. Units shall have knockouts for entrance of low
and line voltage wiring. The control box shall be harness
plug-connected for easy removal.
Piping
Supply and return water connections shall be 1" swivel
ttings. All water piping shall be insulated to prevent
con den sa tion at low liquid temperatures.